The good answer for this is Burning Wheel, as I love it and it’s designed for long-term play, but since I’ve never actually experienced long-term BW, I am going to give my right now answer, which is HERO.

Yeah, HERO.

It could simply be that I have been HERO-focused for a while now, as I’ve been reading a lot of the texts and all of Ron Edwards recent blog posts about Champions.

But, honestly, for all of the ups downs I’ve seen in my HERO play, one of my favorite aspects — which may be true of any point-based RPG — is the slow accretion of advancement. There are no levels, so no specific milestones you shoot for as a player. There’s just the constant drip of XP (= build points) that you receive every session. Whether you spend them immediately on incremental improvement or save them up for a big purchase down the road is up to you. Ergo, play is largely about the play itself, and PC growth feels fairly organic.

Plus, I like the way Disadvantages/Complications inform the campaign as a whole. Those that involve people — both NPC connection and the PC’s role in society at large — can make for great long-term arcs. E.g., the relationship my PC had with his son (a DNPC) in my last big Champions campaign was something I’ll cherish forever. (And holy crap does it resonate even more now that I’m an actual father.)

I dunno. It could be that I have enough distance from my old HERO group and its problems that my glasses have a tint of rose, but I honestly would love another crack at long-term HERO.